Micro gas turbines are emerging as a means for distributed power generation, particularly in areas with little to no electrical grid infrastructure. A gas turbine engine at a minimum has a gas generator, which includes a compressor, a turbine on the same shaft as the compressor and powers the compressor, and a combustion chamber within which fuel is combusted. The turbine of the gas generator is sometimes called a core turbine or a high pressure turbine. The gas generator converts energy produced by the combustion of the fuel into mechanical work in the form of a rotating turbine, which powers the compressor and sustains the gas turbine operation. The operation of the gas turbine engine can be described by the Brayton cycle.
In addition to the gas generator, a gas turbine engine can have a power turbine that accepts exhaust from the turbine to generate additional mechanical shaft power. The power turbine is sometimes called a low pressure turbine. In addition to the power turbine, a gas turbine engine can have an electric generator connected to the power turbine shaft, such that the gas turbine engine produces electric power. In the latter case, the gas turbine engine is also called a gas turbine generator.